oil leak

I have a 76 F350 with 460/C6 (only 65K miles). I have an oil leak at the front of the engine. Oil has sprayed over the distributor cap; puddled in the cavity where distributor enters block and around the dipstick opening. Intake manifold gasket was recently replaced to correct a leak at the rear of the engine. For a couple of years I've been getting some oil in the air filter housing via the crankcase breather hose. I check for this frequently, and lately the filter element in the crankcase filter (inside the air filter housing) has been dislodged from its plastic housing. PCV is new and correctly connected to a new 600 CFM Holly. I've seen other comments on this board (or the performance.digest) regarding oil bing sucked out of the crankcase breather, but don't remember discussion of cause, or correction.

I suppose the new gasket could be leaking at the front, but I really suspect blow-by coming out the dipstick hole because of the spray pattern, e.g., the heater hoses, by-pass hose,upper radiator hose, and alternator all had some oil; it's running down from the top, along the left side of the engine (when viewed from the front). FYI, the ferrule at the top of the dipstick (it surrounds the small pipe that protrudes from the dipstick opening when the dipstick is seated)is loose--does not make a very good seal. It's been like that for a while--certainly pre-dates this latest leak. Leak doesn't normally show-up unless truck is driven at highway speeds for 10 to 20 miles.

Any ideas about what's going on? All inputs/comments/suggestions appreciated.

Don't forget to rule out the oil sensing unit. It should be located toward the left front of the engine. It is similar in size to a spark plug and will cause the problems you mentioned. Oil will spray by the sensing unit but you should also notice a small pool of oil when you park, espically after youv'e run for awhile. The sensing unit only runs about $7.00 and is easy to replace.

Thanks for the suggestion, but on my truck (with guage package) the oil pressure sensor is located at the rear of the engine. It was replaced at the time the leak at the rear of the engine was fixed with the intake manifold gasket replacement.